Center-clip release for printing cylinders



June 3, 1924. 1,496,109

F. O. YOUNG CENTER CLIP RELEASE FOR PRINTING CYLINDERS Filed May 4. 19215 Patented June 3, 1924.

1,496,109 PATENT OFFICE.

1 UNITED STATES FREDERICK 0. YOUNG, 0F NEWTON, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO- THOMAS S. HANNAFORD, 0F WINTHRQLP, MASSACHUSETTS.

CENTER-CLIP RELEASE FOR PRINTING CYLINDERS.

Application filed May 4, 1923. Serial No. 636,554.

To all whom it may concern:

Be it known that I, FREDERICK O. YOUNG, a citizen of the United States, residing at Newton, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Center-Clip Releases for Printing Cylinders, of which the following is a specification.

The present invention relates to rotary and web printing presses and is particularly concerned with the printing or plate cylinders in such presses. Specifically it is an adjunct to the center clips used between adjacent stereotype printing plates for securing them to the cylinder.

The object of the invention is to furnish a means which will automatically free the center clips from the plates when the end clips are loosened, and thereby avoid the need of hammering and incidentally damaging the center clips in order to loosen them.

In the rotary and web printing presse with which this type of clip is used, the printing or plate cylinder is made with a length suflicient to take four stereotype plates in longitudinal alinement, and two plates in circumferential arrangement. These plates may be considered, with respect to their longitudinal order, as comprising two outer or end plates and two inner or middle plates. The two inner plates abut at their inner edges against a rigid fixed rib at the middle of the cylinder which has lips adapted to overlie the beveled inner edges of the plates. Between each inner plate and the adjacent outer plate are intermediate clips which are called center clips and are adapted to overlap and engage both adjacent plates. These center clips are necessarily movable longitudinally of the cylinder in order to engage and release the inner plate. Finally at the ends of the cylinder are the end clips which overlap the beveled outer edges of the end plates. When these end clips are screwed home they press against the end plate, crowding the latter against the center clips and said clips against the innerplate, and finally crowding the inner plate against the stationary central rib of the cylinder. When the plates are to be removed, the end c'lips are ba cked off, leaving the outer plates free to be removed and relieving the binding or crowding pressure on the center clips.

But with the center clips as heretofore made and used, difliculty is met with in clearing them from the inner plates because the soft nature of the metal alloy of which the plates are made causes the clips to be embedded in them more or less and to stick and resist disengagement, even after the clamping pressure of the outer clips and plates has been relieved. The easiest and quickest way, then, to free the center clip is to pound it with a wrench, which the pressman already has in hand for other purposes. This causes the clips, which are made of mild steel, to be more or less deformed. v

In the brief time which frequently is all that can be allowed for changing plates in a newspaper press room, under the hurried conditions obtaining when an edition must be gotten out at a certain time, the pressmen are not able to use as much care in loosening the clips as they could if more time were at their disposal. The result .is that the clips are rapidly knocked out of shape. Their outer edges particularly are offset and deformed so thatthe clips no longer conform accurately in surface contour with the edge of the plate which they are to engage. Thus the trouble due to the clip indenting the inner plate and sticking to it is increased, causing more difiiculty in releasing it and requiring harder and more prolonged hammering for that purpose, and causing still greater deformation which still further increases the difliculty.

' When the clips are so far deformed that they will not properly hold the plates, they must be removed from the cylinder and reset by hammering between dies which restores their original form; but after the resetting operation has been performed'a few times on a clip the holding part begins to crack and separate from the body part. When this happens the clip is useless and must be discarded. I

My invention has for its object to enable the center clips to become automatically disengaged from the inner plate when the outer plate is loosened and removed, and thereby to avoid the need of hammering the center clip to free it from the inner plate and consequently to remove the limitations heretofore existing to the useful life of the clip. The means for accomplishing this object, and the combination thereof with the center I and one oi the possible modifications thereof are illustrated in the "accompanying drawings and described in detail in the following specification.

the drawings Figure 1 is an elevation of a plate cylinder or printing cylinder of a rotaryweb press carrying four plates in longitudinal alinement and illustrating the plate holding means. I

F i-gure '2 is a similar View on ;a larger scale showing one end of the cylinder only and illustrating my invention.

Figure 3 is a longitudinal section of the cylinder on line 33 of Figure 2.

Figure 4 is an end "iew of the cylinder with parts broken away and shown in section.

Figure 5 is a fragmentary sectional view of the guideway in which the center clip is mounted.

Figure 6 is a perspective view of the center clip detached and the preferred form of the means which I have devised for freeing it from the printing plate.

Like reference characters designate the same parts wherever they occur in all the figures. v

The numeral 1 represents the plate cylin der as a whole, which may be considered as typical of the corresponding cylinder provided with any rotary or web press. 2, 2 are the inner printing plates and 3, 3 the outer printing I plates, these being typical stereotype plates which are curved to fit the circa-m terence of the cylinder and have beveled edges 4: to underlie the clips and equivalent holding means. 5 represents the t'runnions or journals of the cylinder by which it is mounted in the journal bearings of the printing press.

The two inner plates abut against a central rib '6, which is an integral part, or at least a permanent and innnoy able part. of the cylinder and is of substantially dove-tailsection having lips which overlap the adjacent beveled edges of the inner plates.

Between the inner "and outer plates are clips 7 which are called center clips: and adjacent to the outer edges of the outer plates are the end clips 8. The center clips are mounted to travel "on guides 9, 9 formed at the opposite sides of recesses 10 which are formed in the cylinder. The clip 7 is made with a body portion 7 having grooves 7 which receive the guides 9, and flanges 7 which underlie said guides. The outer surface of the body portion is flush with the surface of the cylinder, while the plate -holding portion or clip proper is a ribformed on the top of the body and having undercut opposite edges which overlap the adjacent edges of the inner and outer plates. One end 10 or the recess in the cylinder is made large enough to receive the body of the clip when the latter is clear of the guides 9, whereby "the clip can be put in place and removed. An adjustable stop screw 11 threaded into a hole in the clip and provided with a lock nut 12 is provided to prevent the clip from accidentally moving clear of the Ways and falling out of place.

The end clips 8 are similarly mounted in guideways in the end of the cylinder and are engaged with screws 13 which are confined against endwise movement in bearings 14:, whereby they are adapted, when rotated, to force the end clips against the adjacent plate, or to withdraw them. When the end clips are forced against the outer plate they crowd the latter against the center clips, in turn crowding the center clips against the inner plate and forcing the inner plate against the middle rib. The tightening of each set of end clips thus secures two plates. But loosening of the end clips has heretofore not had the effect of releasing the inner plate as well as the outer plate on account of the tendency of the center clip to embed and stick to the inner plate as previously de scribed. Hence. although with the clips heretofore used it has been easy to remove the outer plate, removal of the inner plate has been diflicult. and accomplished only after han'inn-rring the center clip free.

I have by this invention provided spring means which are applied against the center clip from the side thereof which bears on the inner plate. Such spring means are ar-- ranged to be put. under compression when the plates are clamped and are constantly operating on the center clips to free them from "the inner plate when the pressure applied through the outer plate is removed. Theform of spring which I have devised and here chosen for illustration is a helix 15 which is placed in one end portion of the r ecess 10 between the center clip and the adjacent end wall 16 of the recess. The spring surrounds and is guided by a rod 17 which is fastened at one end to the body of the center clip and projects thence into a passage or channel 19 extending from the end of the recess, and in which it has free sliding move- 1116111 That side of the center clip on which the spring is placed is the side toward the middle of the cylinder. or, in other words, the side adjacent to the inner printing plate. The spring, moreover, is of such length that it is put under stress when the clip is moved up against the inner plate. Thus the spring resists placement of the clip in clamping position with respect to the inner plate and tends to displace it from such position; and

acts with the eflect 0t thus displacing it, and releasing the inner plate, as soon as the outer plate has been released and removed. While the springs of all the. clips yield readily enough to permit firm and secure gripping of the inner plate by the center clips when pressure is applied to the latter through the outer plate, nevertheless the springs are powerful enough to free the center clips from the inner plate when the clips are unobstructed at the side toward the end of the cylinder.

A certain and sure release of the inner plate is thus efiiected without any need of hammering the center clip and therefore as the clip is no longer subject to defacement and distortion the limit hitherto existing to its useful life is removed, and in ordinary course it should last as long as the cylinder itself.

What I claim and desire to secure by Letters Patent is:

1. The combination with the plate cylinder of a printing press, of a plurality of printing plates in longitudinal alinement thereon, a center clip between adjacent plates adapted to be brought into clamping relation to one of them by pressure applied through the other, and spring means acting on said clip in a direction to free it from the plate against which it is so pressed, and reacting against a part of the cylinder independently of any printing plate thereon.

2. In a web printing press having a print ing plate cylinder, a center clip mounted with provision for longitudinal sliding movement on said cylinder between the end and the middle thereof, and spring means reacting against the cylinder independently of any printing plate thereon and arranged to resist movement of said clip toward the middle of the cylinder and tending to restore it to a givenposition after being displaced from such position toward the mid dle of the cylinder.

3. In a printing press, a printing plate cylinder having a longitudinal recess equipped with guides, a center clip mounted in said recess and engaged with said guides for sliding movement thereon, an abutment in said recess and clear of any printing plate on the cylinder, and a spring arranged between said abutment and the clip adapted. to react against the abutment and to exert pressure on the clip.

4, In a printing press, a printing plate cylinder having a recess equipped with guides, a center clip mounted in said recess and engaged with said guides, being constrained thereby to move in a given path, and a spring interposed between said clip and the end 01": the recess toward which the clip is moved in gripping an inner plate, said spring being of such proportions that it is put under stress when the clip is brought into gripping position, and tends constantly to displace the clip from such position.

5. In a printing press the combination with a plate cylinder, a recess and guides for a center clip, and a center clip occupying said recess and engaged with said guides, of a rod projecting from one side of the center clip toward the adjacent end of the recess and into a socket formed for its reception in the mass of the cylinder, and a helical spring surrounding said rod and fitting between the center clip and the adj acent end of the recess, said spring being so positioned and arranged that-it is distorted and put under stress when the clip is moved "from normal position into the position for gripping a printing plate.

In testimony whereof I have affixed my signature.

FREDERICK O. YOUNG. 

